The present invention relates generally to AC-DC converters, and more specifically to AC-DC converters used in computer servers and which provide redundancy.
A power supply refers to a source of electrical power wherein electrical energy is supplied to an output load or a group of output loads. Power converters provide for conversion of one form of electrical power to another desired form and voltage. One common example is an AC-DC converter, which converts an AC line voltage to a well-regulated lower-voltage DC current commonly used for electronic devices. Low voltage, low power DC power supply units are commonly integrated with the devices they supply power, such as computers and household electronics.
Power supplies also commonly employ some technique of redundancy to minimize the chances of a system or component losing power. Redundant power supplies are essentially power systems that include two or more units within it, each of which is capable of powering the entire system by itself. Therefore, if for some reason there is a failure in one of the units, the other one can seamlessly take over to prevent the loss of power to the system. In some configurations, one can even replace the damaged unit without powering down the machine. This is commonly referred to as hot swapping, and is commonly used with computer servers or other machines that are used by a large number of people.
Traditional AC-DC converters also use an input rectifier to convert AC power to DC power and also to employ power factor correction (i.e., shape input current to match voltage to provide an improved power factor). Further, that rectified voltage is then converted to a lower voltage output, which actually runs the server.